Characteristics of Cloud Services Tutorial

1.2 'Characteristics of cloud services from a Business Perspective

Hello and welcome to Module No. 1 of Cloud Computing Course offered by Simplilearn! This is a brief introduction to the world of cloud computing.
Cloud computing is basically a service offered over a network by the use of computing resources such as, hardware and software. Cloud computing entrusts remote servers with a user's data, software, and computation.
End-users access cloud-based applications through a web browser, a light-weight desktop, or a mobile app while the business software and users’ data are stored on servers at a remote location.

1.2 'Characteristics of cloud services from a Business Perspective

Hello and welcome to Module No. 1 of Cloud Computing Course offered by Simplilearn! This is a brief introduction to the world of cloud computing.
Cloud computing is basically a service offered over a network by the use of computing resources such as, hardware and software. Cloud computing entrusts remote servers with a user's data, software, and computation.
End-users access cloud-based applications through a web browser, a light-weight desktop, or a mobile app while the business software and users’ data are stored on servers at a remote location.

1.3 Agenda

Let’s look into the topics that will be covered in this module. We will define cloud computing and common terminologies used in it, discuss its essential characteristics, and understand how it is related to virtualization. We will, then, move on to cover what virtualization is and its commonalities and differences with respect to cloud computing. In addition, we will be able to provide common examples of applications using cloud, determine the types of organization who are the best and least suitable for cloud computing, identify different types of cloud services models and their suitability, and finally, look into the different types of deployment models and the differences between them.
Let us now start this module with the definition of cloud computing.

1.4 Definition of Cloud Computing

According to the National Institute of Standard and Testing (NIST), cloud computing has been defined as, “A model for enabling ubiquitous, convenient, on-demand network access to shared pool of configurable computing resources (networks, servers, applications) that can be rapidly provisioned and released with minimal management effort or service provider interaction”.
In simple terms cloud computing is utilizing computing resources, such as, hardware and software which can be delivered as a service over network, typically the Internet.
Cloud is basically a set of hardware, network, storage, services, and interfaces. By using cloud we can offer services, such as, software, infrastructure, and storage. A cloud service provider is entrusted with the responsibility of storing and maintaining the assets. This brings us to the fact that cloud computing, by no means, is a technology; it is rather a business model.
Cloud service providers are responsible for storage of assets and their maintenance. Let us now look into its essential characteristics.

1.5 Essentials Characteristics of Cloud Computing

Although cloud is only a new business model, one might wonder what benefits the consumers enjoy by using cloud. Cloud comes with its own set of advantages and it can be attributed to its characteristics.
It provides on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.
It would be best for us to look at this using an example that’s familiar to all of us. Every one of us would have had the experience of booking a ticket on the travel portal. Now let’s see how this example can help us understand the characteristics of cloud computing better.
A passenger has the flexibility of booking a ticket using a web portal and a login ID. The process is highly simplified and does not require any human interaction. Right from choosing the train to preference of berth— everything is automated. This is the On-demand self-service that cloud offers where the consumers can automatically set-up computing capabilities, such as, storage and server time as and when the need arises.
Likewise the passenger is able to book his tickets via internet through any mobile devices, such as, tablet, phone, or laptop that has access to a network. This Broad network access is a quality that consumers enjoy because of cloud services.
Now, let us understand Resource pooling through an example. We know that trains have the capacity to occupy hundreds of passengers for a single trip. Several passengers, travelling to the same destination, board a single train and are assigned separate berths according to their needs. This is similar to what cloud does where multiple consumers are able to access virtual resources that are assigned to them. There is a sense of location independence where the consumer is generally unaware of specific details of the location. However, he is aware of it in a much higher level, such as, country, state, etc. Resources pooled, similarly, can be storage, network bandwidth, memory, etc.
Rapid elasticity is one more characteristics of cloud computing. It is nothing but scaling up or scaling down of resources according to demand. Considering our previous example, when the total numbers of passengers do not occupy all the coaches, the coaches can be disengaged and joined with another train that has more number of passengers. Similarly in cloud, resource utilization can be increased or decreased according to the consumer needs.
Measured service is the last one. When a passenger travels by train he or she only pays for the amount of distance travelled by the individual and not for the entire the journey of the train. Likewise, resource usage is monitored by the provider and charged only for what has been utilized by the consumer. This is the typical pay-per-use or charge-per-use method that is practiced.

1.6 Cloud Computing Examples

Although Cloud computing has become a buzz word in recent times, it has been around for a while now. Some early examples of cloud computing include virtual private network or VPN, centralized storage leading to server virtualization, web application accessed over any network. The most familiar amongst them is shared e-mail storage such as gmail, hot mail and so on.

1.7 Definition of Virtualization

We will now move on to the next topic which is virtualization. This is the enabling technology that drives cloud computing and the different services that it offers.
This technology began a decade ago when a webserver was a separate server where every website was run on a separate machine. A revision in the http protocol enabled the running of multiple websites on single machine. This introduced the concept of a virtual webserver. Virtualization is nothing but a means of creating a virtual version of the device or resource, such as, servers, storage, and network where the resources can be separated into execution environments. Even a simple partitioning of a hard drive is considered virtualization because we take one drive and partition it into two separate drives. The same can be applied to storage, server, operating system, and even networks.
As it has been mentioned, virtualization is the technology that enables cloud computing model to exist because in cloud it is essential to separate the resources from their physical location.
As a result of this integration of software, hardware, and multiple processes the delivery, management, and sharing of IT assets have been simplified to a great extent.
In the next slide, we will discuss the similarities and differences between cloud computing and virtualization.

1.8 Commonalities and Differences

Here, we will discuss several attributes of cloud computing which are similar to or different from virtualization.
Cloud and virtualization create an “abstraction layer,” i.e., the end user is unaware of the specific details of the location of the servers, the type of hardware that is provisioned to him or her, etc.
Both follow a simple multi-tenant model, or, in other words, multiple users share a singular space. Sharing of resources is the sole purpose of both cloud and virtualization.
As, we have discussed earlier in the module, cloud offers immense flexibility to its users. Similarly, virtualization also offers this flexibility where the user can provision resources depending on the demand. They can scale-up when the demand is high and also scale down with ease the demand ceases.
Although cloud and virtualization have so many attributes in common there is a primary difference between them. Cloud computing is merely a business model whereas virtualization is a technology. It is the technology that drives cloud computing.
The next slide discusses the suitability of cloud computing to various organizations.

1.9 Suitability of Cloud Computing of Organizations

When we talk about cloud computing suitability, not all organizations are carved for the benefits of cloud computing due to several characteristics.
Cloud computing is best suited for businesses which change rapidly, or the ones which scale up and down, or for the companies using technologies which is still immature.
Also, in companies where the capital investment is scarce or very expensive, cloud can be used. By using cloud, Capital-expenses are converted to Operational-expenses, i.e., instead of owning servers they can be leased using cloud. Companies which are stringent on their budget can avail this option.
Cloud suits companies where senior management is not willing to make long-term commitments due to vendor lock-in or in situations where it is a one-time requirement. In such cases, cloud is highly beneficial because there are no issues, such as, vendor lock-in which means an organization can use cloud as and when the need arises and need not worry about a long term contract. This can be compared to outsourcing where a company goes to an external vendor for specific requirements. There is no term agreement that they share.
Now we will discuss the organizations which are not suitable for cloud computing.

1.10 Non Suitability of Cloud Computing of Organizations

While some companies benefit greatly from cloud computing, there are some organizations which are not quite suitable for it. We will discuss about this here.
Companies that have a fixed and steady workload on a day-to-day basis have no need for cloud computing. These companies use their physical resources, such as, hardware to its optimal best and there is barely the need for scaling.
Also, companies that operate on a huge scale usually own their own data centers. When they own data centers they usually have enough scale to be flexible like the cloud providers. Hence, there is no need for cloud. However, they can be benefited from virtualizing their infrastructure, instead.
Cloud is not preferred in companies which have to comply with standards for security reasons, because the consumer will need more details about the location of its data and servers than what a cloud provider usually provides.
Similarly, in organizations with systems which require a high degree of operational assurance, such as, military systems, health, safety, and emergency responses may be bad fit due to the weak guarantees offered by public cloud services.
In spite of their non-suitability for some organizations, cloud and virtualization are still widely accepted. Let us now discuss the reasons for its adoption.

1.11 Reasons for Adoption

Cloud and virtualizations are beneficial to tackle issues, such as, running out of capacity, expensive excess capacity, and tied-up capital. Let us see how.
When the number of people in a company is on a steady rise, the company can face issues, such as, capacity management. Likewise, when companies open offices in new locations, this issue arises. In such cases, cloud computing comes in handy. With its quality to scale-up and scale-down capacity, upgrades are easy.
Similarly, companies have to invest in capacity from time to time in order to upgrade their systems. Instead, opting for cloud would be more thrifty option as scaling up their resources is not as expensive as investing in a new capacity. Moreover, in many companies there is not maximum utilization of capacity at all times. In such situations cloud helps, as scaling up and down is possible with it.
In addition, companies need not invest in servers and storage. Instead, they can opt for cloud services that offer the necessary infrastructure. This leads to less investment in hardware.
The next topic, that we will discuss, is the services models that cloud offers.

1.12 Different Service Models of Cloud Computing

Cloud computing offers three different service models according to the need of the consumer.
The first model is Software as a Service (SaaS) (pronounce as “S-A-A-S”) – This offers the consumer the capability to use the provider’s applications available on a cloud infrastructure. Cloud infrastructure is basically a collection of both hardware and software, available virtually, enabling the characteristics of cloud computing.
These applications can be accessible using a thin client interface, such as, a web browser (web-based e-mail) or a program interface. The consumer does not have to manage or control the underlying infrastructure including the network, storage, operating system, or even individual application capabilities, with the exception of limited user-specific application configuration settings.
The second model is Platform as a Service (PaaS) (pronounce as “P-A-A-S”) – This offers the consumer the capacity to deploy acquired or consumer-created applications on to the cloud infrastructure using programming languages, libraries, services, and tools supported by the provider. In addition, this capability does not preclude the use of compatible languages, libraries, services, or tools from other sources. Similar to SaaS, the consumer does not manage the underlying cloud infrastructure.
The third model is Infrastructure as a Service (IaaS). (pronounce as “I-A-A-S”) In this case, the consumer has the ability of provision processing, storage, network, and other fundamental computing resources where the consumer himself is able to deploy and run software which can include operating systems and applications. The consumer once again does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications, and possibly limited control over selected networking components (host firewalls).
In the next two slides we will discuss the deployment of models of cloud computing.

1.13 Deployment Models of Cloud Computing

Like different service models in cloud computing there are multiple deployment models through which these cloud services are delivered. The different deployment models are private cloud, community cloud, public cloud, and hybrid cloud.
In a private cloud set-up, the infrastructure is provided exclusively to a single company or organization. Multiple users (different business units) within the same organizations can use it. In this case, the infrastructure may be owned, managed, and operated by the organization itself, or a third party, or even have a combination of both. It can exist on or off the premises. For example: A university or company owning a cloud for only the members.
In a community cloud, the infrastructure is provided exclusively to a specific community of users which can include users from different companies but with the same requirements. For example: mission, security requirements, and compliance issues. In this case, it can be owned, managed, and operated by one or more companies within the community, or a third party, or a combination of both. Like private cloud, it can exist either on or off premises. For example: SaaS offerings for specific user groups, government clouds.
In a public cloud, the infrastructure is provided for open use by the general public. It can be owned, managed, and operated by a business, academic, government organization, or a combination of all of them. Again, it can exist either on or off premises. Example: Amazon web services, Windows Azure.
In the next slide, we will continue with our discussion of deployment of models of cloud computing.

1.14 Deployment Models of Cloud Computing (Contd.)

The last one is the hybrid cloud, which is a composition of two or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized technology enabling data and application portability. For example: Websites which are partly served out of private data centers and partly out of public clouds, potentially even depending on the actual load.

1.15 Summary

With this we have come to the end of this module where we discussed the definition of cloud computing, the common terminologies used in it, its essential characteristics, and how it is related to virtualization. We also learnt what virtualization is and its commonalities and differences with respect to cloud computing. We are now able to list out a few common examples of applications using cloud computing and identify the types of organizations who are best and least suitable for it. We also discussed different types of cloud services models and their suitability, the different types of deployment models, and the differences between them.
In the next module, we will evaluate cloud computing from business perspective.
We will now go through a small quiz in order to judge our knowledge and understanding of this module.